xxiv PREFACE TO THIRD SECTION 
determine the presence of tin, or of zinc, in a 
state of combination with copper : for if there be 
a particle of zinc in th^ mass, the work, consist- 
ing of brass, and not oi bronze, is thereby proved 
to be either of modern date, or, at best, a 
specimen of orichalctnn, and therefore of Roman 
In the acknowledgment of literary obligations, 
the author has been scrupulously exact; per- 
haps more so than, in some instances, might 
seem necessary: but it was his wish to dis- 
charge every debt of this nature, — for two 
reasons: first, because by so doing he presents 
his Reader with a view of the society in which 
he has lived, and introduces to his notice some 
of the friends with whom he has conversed: 
secondly, because those parts of his work which 
are exclusively his own, and for which he alone 
is responsible, may the more easily be re- 
cognised. Upon the present occasion he is 
desirous of acknowledging a communication of 
an interesting nature from his friend the Rev. 
G A. Broavne, M.A. Fellotv of Triniti/ College, 
Cambridge, which constitutes the first article of 
(1) See. f-Fatson on Orichalcum. Chem. Essays, vol.W. /). 85. 
Lamb. 1786. 
